Aspen Global Change Institute (AGCI) Interdisciplinary Science Workshop: Decadal Climate Prediction; Aspen, CO; June 22-28, 2008

2007年政府间气候变化专门委员会（IPCC）评估报告AR4中出现的一个引人注目的问题是对2030年左右的“短期”气候预测的兴趣。这是许多决策支持活动和影响感兴趣的时间框架，但目前的模型和实验没有明确地解决这个问题。目前提供的任何短期气候信息都是取自21世纪模拟早期阶段相对粗糙的网格全球耦合气候模式，这些模拟始于19世纪末，运行到2100年及以后。虽然这提供了关于气候系统在近期时间尺度上对外部强迫的响应的一些信息，但最近人们认识到，使用具有更高空间分辨率的模式和可能观测到的初始状态的不同类型的实验可以为未来几十年的决策支持和其他应用提供更好的区域气候变化信息。阿斯彭全球变化研究所（AGCI）在2006年夏季的一次会议上首次提出了下一轮协调气候变化实验的实验设计，其中明确包括短期气候预测，供国际气候模拟界进行评估。从那时起，世界气候研究计划（WCRP）、国际地圈/生物圈计划（IGBP）和政府间气候变化专门委员会（IPCC）开始着手这项工作，其中WCRP的气候变率和可预测性计划（CLIVAR）将年代际预测作为气候模拟界的下一个重大研究挑战。2008年的AGCI会议延续了2006年会议的中断，并将这一概念提升到一个新的水平，不仅解决了涉及设计和运行短期气候预测（现在更常被称为“十年预测”）的艰巨科学问题。会议还讨论了这些信息在决策支持和影响研究中的效用和应用的重要问题。组织者邀请了从事十年预测研究的美国和国际建模小组的专家，以及将使用这些信息的决策支持和影响社区的代表。本次会议的成果将是一份白皮书，概述关于年代际预测的知识现状、此类实验的预期成功程度、与此问题相关的科学挑战的可能解决方案，并评估如何将这类气候变化信息用于未来几十年的决策支持和影响分析。更广泛的影响主要包括对近期（在代际时间尺度上）气候变化的社会适应规划的年代际预测的巨大价值。

A compelling issue that emerged from the Intergovernmental Panel for Climate Change (IPCC) Assessment Report, AR4, in 2007 was the interest in "short term" climate projections out to about 2030. This is a time frame of interest for many decision support activities and impacts, but is not explicitly addressed with current models and experiments. Any short-term climate information currently provided is simply taken from relatively coarse grid global coupled climate models in the early stages of 21st century simulations that began in the late 1800s and are run to 2100 and beyond. While this provides some information regarding the response of the climate system to external forcing on near-term time scales, it has recently been recognized that a different type of experiment using models with higher spatial resolution and possibly an observed initial state could provide better regional climate change information for decision support and other applications over the next few decades. An Aspen Global Change Institute (AGCI) session in the summer of 2006 first proposed an experimental design for the next round of coordinated climate change experiments that explicitly included short-term climate predictions to be performed for assessment by the international climate modeling community. Since then this has been taken up by World Climate Research program (WCRP), International Geosphere/Biosphere Program (IGBP) and the IPCC, with the WCRP's Climate Variability and Predictability Program (CLIVAR) targeting decadal prediction as the next big research challenge for the climate modeling community. The AGCI session in 2008 takes up where the 2006 session left off, and carries this concept to the next level by tackling not only the formidable science issues involved with designing and running short term climate projections (now more commonly referred to as "decadal prediction"). The session also addresses the important issues of the utility and application of this information for decision support and impacts research. The organizers invited U.S. and international experts from modeling groups doing research in decadal prediction, as well as representatives from the decision support and impacts communities who would use this information. Output from this session will be a white paper summarizing the current state of knowledge on decadal prediction, the degree of success one could expect from such experiments, possible solutions to the scientific challenges involved with this problem, and an assessment of how this type of climate change information could be used for decision support and impacts analyses the next few decades. Broader impacts include, primarily, the large value of decadal prediction for societal adaptation planning for near term (on generational time scales) climate change.